Sound-amplifier



UNITED STATES WILSON F. SMITH, OF EAST LIVERPOOL, OHIO.

SOUND-AMPLIFIER.

i specification of Letters Patent.

Patented Mar. 1, 1921.

Application led January 4, 1919. Serial No. 269,649.

T o all 'whom 'it may concern:

Be it known that I, VVILsoN F. SMITH, a citizen of the United States of America, residing at East Liverpool, in the county of Columbiana and State of Ohio, have invented new. and useful Improvements in Sound-Amplifiers, of which the following is a specification. l

The object of the invention is to provide a sound amplifier as a means of confining and directing a resonating column of air, which shall be capable of concentrating and rendering sonorous the tones, simple and comrpound of i musical instrument or a repro ucing apparatus such as a phonograph, while preserving with integrity the relative values of the'fundamental and overtones or harmonics and which shall not, through sympathetic vibration unduly emphasize the latter, and particularly the dissonant harmonics which, while serving in their normal and subordinate values relative to the fundamental and consonant overtones to enrich the tone, produce a disagreeably discordant impression upon the ear when they become disproportionately prominent.

To this end the invention consists in proM viding an amplifier of relatively non-rcso nant material, incapable of responding with any perceptible degree of sympathy, either as a whole or in part to the relatively short and rapid vibrations incident to the overtones, and in providing the wall of the amplifier with a surface which while generally smooth or regular is minutely broken, irregular or granular, so that as the sound waves impinge thereon the broader and longer vibrations of the fundamental and consonant overtones are subject to the concentrating and amplifying effect of the shape of the device as a unit While the tendency is to disperse or merge the short sound waves of the dissonant overtones instead of directly reiiecting them as when a glazed. or polished surface is provided for their contact.

In other words, the invention consists in providing a device of this class which shall eliminate or 'at least minimize both sy1npathetic vibration of the medium itself, such as a horn or its equivalent, and the direct reection of the shorter Sound waves, which represent the dissonant overtones, and thus dispense with the collateral and undesirable sound effects which are incident to metallic, wooden, glass and porcelain amplifiers and others which arenot only resonant and subject to sym pathetic nodal vibrations but are polished, varnishcd, planished, glazed or otherwise finished toprovide sensitivelyreflective surfaces.

ln carrying out the invention the sound wave concentrating and amplifying medi um, which may be of the horn shape illustratcd in the drawing is constructed of baked clay.

The wall is preferably of uniform thickness throughout, with the bell i() connected with the sound receiving terminal, or inletV ll by a neck which may curry au integral bracing web l2.

Also, the bell, as indicated may be of ellip tical form, but modifications in shape may be resorted to without departing from the principle involved, and which is best exemplified in providing the device with a wall of' amorphous or non-crystalline structure, without grain or lamina, but of minutely granular material, such as clay, suitably shaped and baked and finished with an unglared and unpolishcd inner surface which, while generally smooth or regular in contour is minutely rough or granular as produced' by the molding'ol' the plastic clay, and which by reason of these characteristics 1s possessed of the properties herein beforespecifically described.

The invention having been describethwhat is claimed as new and useful is:--

l. A sound amplifier having a wail of baked clay. v

2. A sound amplifier having a wali surface of unglazed baked clay.

3. .A sound amplifier having a wali of baked clay provided with an unglazed reflecting surface.

li. A sound amplifier having a wali previded with a granular surface.

In testimony whereof I affix my signature.

WILSON F. SMITH. 

